# A Text-book of Theodolite Surveying and Levelling: For the Use of Students in Engineering, Land, and Mine Surveying

Charles Griffin, 1922 - Azimuth - 562 pages
Hocken Collections copy stamped: Donated to the Surveying Dept by the estate of Andrew Robb, died 5/12/1974.

### Contents

 CHAPTER X 136 CHAPTER XI 154
 Mining TheodolitesMeridian Benchmarks at MinesMarking 496 INDEX 553

### Popular passages

Page 47 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides.
Page 152 - Similar triangles are to one another in the duplicate ratio of their homologous sides.
Page 167 - The sides of a triangle are proportional to the sines of the opposite angles.
Page 362 - If a ray of light suffers two successive reflections in the same plane by two plane mirrors, the angle between the first and last direction of the ray is twice the angle of the mirrors. D is set parallel to CX, and mirror C turns with arm B. The angle between SC and S...
Page 107 - The area of a triangle is equal to half the product of any two of its sides multiplied by the sine of the included angle, radius being unity.
Page 230 - ... at greater distances than those of Duddell's experiments, which only extended to sixty miles, we find from simple mathematical, or rather geographical, considerations that the radius of the circle in which the...
Page ii - Genetically Considered— Ores and Minerals Considered Economically.— Mine Sampling and Ore Valuation.— The Examination and Valuation of Mines.- INDEX. " A work which should find a place in the library of every mining engineer.
Page 204 - The difference between the two readings on the arc brought to seconds, divided by the difference of the two readings of the object end of the bubble, gives the value of one division of the level in seconds of arc. Thus :— Elevation. 01-jcct end of bubble. 1st observation . . . 7� 3 28" 18 divisions 2nd ,,...700 6 Difference . . . o 3 28 12 Value of one division = = 17
Page 72 - Therefore, the sum of the northings should equal the sum of the southings.
Page 228 - <>••, an arc of the horizon intercepted between the meridian of a place and the vertical circle passing through the centre of a celestial object.